knock back vs toss off

knock back

verb
  • To drink an alcoholic beverage swiftly or often. 

  • To stun; to surprise. 

  • To press or knead (dough) so as to remove air bubbles. 

  • To reject; to refuse. 

toss off

verb
  • To drink up rapidly. 

  • To masturbate. 

  • To assemble hastily. 

  • To deliver in an offhand manner. 

How often have the words knock back and toss off occurred in a corpus of books? (source: Google Ngram Viewer )